Device and method for sealing an ink cartridge

ABSTRACT

The present invention provides a sealing device and method for an ink cartridge. First, the ink cartridge and a sealing film are placed in an airtight chamber isolated to the atmosphere. Second, a decompression mechanism is used to draw the air off the airtight chamber until the air pressure in the airtight chamber is reduced to a pre-determined pressure. Finally, a sealing mechanism is used to seal the sealing film onto the ink cartridge.

BACKGROUND OF THE INVENTION

[0001] 1. Field the Invention

[0002] The present invention relates to a device and method for sealing an ink cartridge. In particular, the present invention relates to a device and method for sealing an ink cartridge using a decompression chamber.

[0003] 2. Description of the Related Art

[0004] Generally speaking, a detachable ink cartridge includes a cover, a body, and an ink holder. The cover comprises an ink-supplying hole, an air opening and an air passage. After the ink is infused into the ink cartridge, a sealing film is used to seal the cover such that the ink in the ink cartridge is not vaporized or changed in character during transportation and preservation. When the ink cartridge is to be used, the sealing film is removed from the cover. Then, the ink cartridge is fitted into an ink jet mechanism to perform printing.

[0005] The printing performance depends on the sealing quality. FIG. 1 shows a conventional sealing device. Under a certain high temperature and pressure, the sealing film 5 is covered on a cover 7 of an ink cartridge 6 by a heater 4. Though this simple sealing device takes a shorter time to seal the ink cartridge 6, the sealing is not uniform across the cover 7. As shown in FIG. 2, bubbles are formed between the sealing film and the cover of the ink cartridge because the air, which is subject to a thermal expansion effect, can not be expelled off during the thermal sealing. These bubbles result in a non-uniform sealing and an unsightly appearance. Further, these bubbles expand to cause the sealing film to break under high temperature or low pressure conditions. Thus, a leakage of ink occurs. In order to overcome the aforementioned problem, the U.S. Patent No. 5,875,615 discloses a method for sealing the ink cartridge. As shown in FIG. 3, an ink cartridge 1 is placed obliquely on a pallet 20. Simultaneously, the ink cartridge 1 is heated such that the air in the ink cartridge 1 can be expelled due to the thermal expansion effect. Finally, a heating plate 38 is used to seal a sealing film 19 on the cover 11. However, the method provided by the prior art does not have an evident improvement in sealing the ink cartridge. Furthermore, it requires additional sealing mechanisms and procedures to keep it prone during the thermal sealing, thus causing a high manufacturing cost.

SUMMARY OF THE INVENTION

[0006] An object of the invention is to provide a device and method for sealing an ink cartridge. The sealing device comprises an airtight chamber having an upper airtight cover, a lower airtight cover and a cartridge supporting pedestal, the cartridge supporting pedestal being disposed in the lower airtight cover for supporting the body of the ink cartridge; a decompression mechanism connected to the airtight chamber for drawing the air off the airtight chamber; and a sealing mechanism disposed in the airtight chamber, the sealing mechanism having a sealing head for sealing a sealing film on the cover of the ink cartridge.

[0007] The sealing method comprises the steps of: (a) Placing the body of the ink cartridge in the cartridge supporting pedestal of the lower airtight cover of the airtight chamber; (b) Placing the sealing film on a sealing position on the cover of the ink cartridge; (c) Closing the upper airtight cover to the lower airtight cover; (d) Actuating the decompression mechanism to draw the air off the airtight chamber until the air pressure in the airtight chamber is reduced to a pre-determined pressure, wherein the pre-determined pressure is less than the air pressure surrounding the airtight chamber; (e) Turning off the valve of the decompression mechanism; and (f) Pressing the sealing head to the sealing position on the cover of the ink cartridge to thermally fuse the sealing film onto the cover of the ink cartridge, wherein the sealing head is pre-heated to a pre-determined temperature.

[0008] A detailed description will be given by the following embodiments with reference to the accompanied drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:

[0010]FIG. 1 shows a conventional sealing device for an ink cartridge;

[0011]FIG. 2 shows a defective ink cartridge with bubbles between the sealing film and the cover;

[0012]FIG. 3 shows another conventional sealing device for an ink cartridge;

[0013]FIG. 4 shows the sealing device of the present invention;

[0014]FIG. 5a shows a sealing film placed in the airtight chamber of the present sealing device;

[0015]FIG. 5b shows an ink cartridge placed in the cartridge supporting pedestal;

[0016]FIG. 6a shows the upper airtight cover closed to the lower airtight cover to form the airtight chamber;

[0017]FIG. 6b shows an elastic airtight member used in the airtight chamber;

[0018]FIG. 7a shows the sealing head pressed down on the cover of the ink cartridge;

[0019]FIG. 7b shows the sealing film thermally fused to the cover of the ink cartridge by the sealing head; and

[0020]FIG. 8 shows an ink cartridge sealed by the sealing device of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0021] Referring to FIG. 4, the sealing device of the invention comprises an airtight chamber 100, a decompression mechanism 200 and a sealing mechanism 300. The airtight chamber 100 includes an upper airtight cover 110, a lower airtight cover 120, a cartridge supporting pedestal 130 and an elastic airtight member 140 such as an O-ring. The decompression mechanism 200 includes a pump 210, a valve 220 and a drawing pipe 230. The drawing pipe 230 is connected between the pump 210 and the valve 220 and between the valve 220 and the upper airtight cover 110. The sealing mechanism 300 includes a sealing head 310 and a cylinder 320.

[0022] Referring to FIG. 5a and FIG. 5b, an ink cartridge 900 is placed in the cartridge supporting pedestal 130. The cover 910 of the ink cartridge 900 is faced upward and below the sealing head 310. Then, a sealing film 700 is placed on a sealing position between the cover 910 and the sealing head 310. It is noted that the sealing position covers an ink-supplying hole 910, an air opening 912 and an air passage 913 of the cover 910 of the ink cartridge 900.

[0023] Referring to FIG. 6a and FIG. 6b, the upper airtight cover 110 is closed to the lower airtight cover 120 so as to form the airtight chamber 100. In addition, the elastic airtight member 140 disposed in the lower edge of the upper airtight cover 110 is utilized to isolate the airtight chamber 100 from the atmosphere. Then, the pump 210 and the valve 220 are actuated to draw the air off the airtight chamber 100. When the air pressure in the airtight chamber 100 is reduced to a certain predetermined value, for example 640±20 mm-Hg, the valve 220 is turned off.

[0024] Referring to FIG. 7a and FIG. 7b, the sealing head 310 is pressed down such that the sealing film 700 is thermally fused to the cover 910 of the ink cartridge 900, wherein the sealing head 310 is pre-heated to a temperature of 180±10° C. The sealed film 700 covers the ink-supplying hole 911, the air opening 912 and the air passage 913.

[0025] The ink cartridge sealed by the sealing film 700 is shown in FIG. 8. Because the sealing device uses decompression as a sealing step in sealing the ink cartridge, there is no bubble formed between the sealing film and the cover, and thus the sealing film is strongly attached on the cover of the ink cartridge. In addition, because the inner pressure of the ink cartridge remains less than 1 atm. after sealing, there is a pressure difference between the interior and the exterior of the ink cartridge. Therefore, subsequent to the sealing process, the sealing film is more strongly sealed on the cover of the ink cartridge due to the pressure difference.

[0026] The advantage of using the decompression mechanism of the invention is that the sealing temperature of the sealing head can be reduced such that the operating life of the sealing head can be prolonged. Furthermore, the sealing speed can be increased while the incidence of failure of sealing can be reduced.

[0027] While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. 

What is claimed is:
 1. A sealing device for an ink cartridge having a cover and a body, comprising: an airtight chamber having an upper airtight cover, a lower airtight cover and a cartridge supporting pedestal, the cartridge supporting pedestal being disposed in the lower airtight cover for supporting the body of the ink cartridge; a decompression mechanism connected to the airtight chamber for drawing the air off the airtight chamber; and a sealing mechanism disposed in the airtight chamber, the sealing mechanism having a sealing head for sealing a sealing film on the cover of the ink cartridge.
 2. The sealing device as claimed in claim 1, wherein the airtight chamber further includes an elastic airtight member disposed in the lower edge of the upper airtight cover, whereby the airtight chamber is isolated to the atmosphere when the upper airtight cover is closed to the lower airtight cover.
 3. The sealing device as claimed in claim 1, wherein the sealing mechanism further includes a cylinder for moving the sealing head.
 4. The sealing device as claimed in claim 3, wherein the sealing head is connected to the cylinder and is faced toward the cartridge supporting pedestal.
 5. The sealing device as claimed in claim 1, wherein the decompression mechanism further includes a pump and a valve.
 6. The sealing device as claimed in claim 5, wherein the decompression mechanism further includes a drawing pipe connected between the pump and the valve and between the valve and the upper airtight cover.
 7. A sealing method for using in the sealing device as claimed in claim 1, comprising the steps of: (a) Placing the body of the ink cartridge in the cartridge supporting pedestal of the lower airtight cover of the airtight chamber; (b) Placing the sealing film on a sealing position on the cover of the ink cartridge; (c) Closing the upper airtight cover to the lower airtight cover; (d) Actuating the decompression mechanism to draw the air off the airtight chamber until the air pressure in the airtight chamber is reduced to a pre-determined pressure, wherein the pre-determined pressure is less than the air pressure surrounding the airtight chamber; (e) Turning off the valve of the decompression mechanism; and (f) Pressing the sealing head to the sealing position on the cover of the ink cartridge to thermally fuse the sealing film onto the cover of the ink cartridge, wherein the sealing head is pre-heated to a pre-determined temperature.
 8. The sealing method as claimed in claim 7, wherein in the step (f), the sealing head is actuated by the cylinder.
 9. A sealing method for an ink jet cartridge, comprising the steps of: (a) Disposing the ink jet cartridge in an airtight chamber; (b) Decompressing the airtight chamber; and (c) Sealing a film onto the ink jet cartridge.
 10. The sealing method as claimed in claim 9, wherein the step (a) further comprises the sub-steps of: (a-1) Placing the ink jet cartridge in a cartridge supporting pedestal of the airtight chamber; (a-2) Placing the film on a sealing position on the ink jet cartridge; and (a-3) Closing the airtight chamber.
 11. The sealing method as claimed in claim 9, wherein the step (b) further comprises the sub-steps of: (b-1) Actuating a decompression mechanism to draw the air off the airtight chamber until the air pressure in the airtight chamber is reduced to a pre-determined pressure, wherein the pre-determined pressure is less than the air pressure surrounding the airtight chamber; and (b-2) Turning off the decompression mechanism.
 12. The sealing method as claimed in claim 9, wherein the step (c) further comprises the step of Pressing a sealing head to the sealing position on the ink jet cartridge to thermally fuse the film onto the ink jet cartridge, wherein the sealing head is pre-heated to a pre-determined temperature.
 13. The sealing method as claimed in claim 12, wherein the sealing head is actuated by a cylinder. 